What the ratings mean for fit
The Siemens SENTRON 3VA1180-5EF36-0HC0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection. Its headline number is the 80 A rated continuous current (Iu) at 40 °C, which holds flat to 80 A up to 50 °C before derating to 72 A at 70 °C — so in a warm panel you lose about 10 % of the continuous rating. The breaking capacity tells the real story: 187 kA at 240 V, 121 kA at 415 V, 75.6 kA at 440 V, and 17 kA at 690 V. That 187 kA figure at 240 V means it can safely interrupt a fault current up to that level without cascading upstream — critical for high-fault utility feeds or transformer secondaries where standard MCBs would weld shut. The overcurrent release is a TM240 thermal-magnetic type — no electronic adjustment, no communication function, no phase-failure detection. It is a straightforward line-protection breaker for fixed-current loads. The auxiliary contact version carries 2 HQ (high-capacity) switches, and the integrated auxiliary trip is order code 3VA9688-0BL30. A shunt trip (STL) is fitted as the auxiliary release design, with no undervoltage release. The voltage trigger is present, meaning remote tripping via the shunt coil is supported. Mounts on a DIN rail or panel base — the 70 mm depth and 76.2 mm width fit standard SENTRON 3VA cutouts. IP40 on the front means it is protected against tools and wires >1 mm but not against water ingress; keep it inside a dry enclosure. Rated insulation voltage Ui is 800 V, and latching endurance is 15,000 cycles. Storage range is -40 °C to 80 °C; operating range is -25 °C to 70 °C.